ABSTRACT
Objective To compare the cerebral blood flow (CBF) and intracranial pressure (ICP) during laparoscopic gynecologic surgery performed under propofol and sevoflurane combined anesthesia.Methods Forty ASAⅠ orⅡ patients aged 20-59 yr weighing 44-69 kg were randomly divided into 2 groups(n=20 each):propofol group (group P) and sevoflurane group (group S).Anesthesia was induced with TCI of propofol (Ce 4μg/ml) in group P or 8% sevoflurane in group S combined with TCI of remifentanil (Ce 6 ng/ml).Tracheal intubation was facilitated with cis-atracurium 0.15 mg/kg.The patients were mechanically ventilated.PETCO2 was maintained at 35-40 mm Hg.Anesthesia was maintained with TCI of propofol or sevoflurane.inhalation combined with TCI of remifentanil.BIS value was maintained at 45-50 by adjusting Ce of propofol or concentration of sevoflurane.Intraabdominal pressure (IAP) was maintained at 12-14 mm Hg.Transcranial Doppler monitoring wag used.Cerebral blood flow velocity (CBFV) and pulsatility index (PI) were recorded at 5 min after supine position(T1)and 5 min after supine lithotomy position before induction(T2),while tracheal tube was being inserted(T3),5 min after tracheal intubation(T4),immediately and 15 min after abdominal CO2 iusnfflation in trendelenburglithotomy position (T5,T6) and at 10 min after deflation of abdomen(T7).Results CBFV was significandy decreased at T3,T4 and T7 in group P and at T4 and T7 in group S as compared with the baseline at T1.CBFV at T3 was significantly lower in group P than in group S.PI at T3,T4 was significantly decreased in group P as compared with the baseline at T1 and was significantly lower than in group S.PI at T5,6 was significantly increased as compared with the baseline in both groups but was not significantly different between the 2 groups.Conclusion When combined with remifentanil.propofol could decrease CBF and ICP while sevoflurane has no significant effect on CBF and ICP after induction.CBF and ICP are significantly increased in both groups after abdominal CO2 insufflation.
ABSTRACT
Objective To investigate tbe pharmacodynamics of different local anesthetics administered intrathecally for caesarean section. Methods Ninety-six parturients with singleton term pregnancies undergoing caesarean section under combined spinal-epidural anesthesia were enrolled in this study. The patients were randomly divided into 3 groups ( n = 32 each ) and received intrathecal (IT) 0.5 % bupivacaine, 0.5 %levobupivacaine and 0.5% ropivacaine respectively. The initial doses was 9 mg in all 3 groups. The ratio of two successive doses was 0.9. If the upper sensory block reached T7 or above and there was no need for additional dose in the 45 min after the initial dose, the IT analgesia was considered to be effective. The median effective dose ( ED50 ), the 95 % effective dose( ED95) and 95 % confidence interval (95 % CI )were calculated by Dixon. Results The ED50 and ED95 and 95%CI of bupivacaine were 6.15 (95%CI 5.48-6.68) mg and 7.62 (95%CI 6.91-11.82) mg; of levobupivacaine were 8.06 (95%CI 7.46-8.62) mg and 9.59 (95%CI 8.86-13.42) mg;of ropivacaine were 10.55 (95%CI 9.73-11.49) mg and 12.80 (95%CI 11.66-21.42) mg. The relative potency potency ratio between bupivacaine, levobupivacaine and rupivacaine is 1.00:0.76:0.58.
ABSTRACT
Objective To observe the effects of propofol or sevoflurane combined with remifentanil on cerebral blood flow (CBF) and cerebral autoregulation in patients undergoing gynecologic laparoscopic surgery. Methods Forty patients were randomly divided into two groups: the propofol group (group P, n=20) and the sevoflurane group (group S, n=20). Anaesthesia was induced with target-controlled infusion (TCI) of propofol and remifentanil in group P, with an inhaled induction of sevoflurane and TCI of remifentanil in group S, respectively. The depth of anesthesia was regulated according to bispectral index (BIS). The pressure of end-tidal carbon dioxide (P_(ET)CO_2) was kept at 35-40 mmHg by mechanical ventilation. The mean arterial pressure (MAP), heart rate (HR), pressure of arterial carbon dioxide (PaCO_2), P_(ET)CO_2, time-averaged peak flow velocity (TAP) and the transient hyperaemic response ratio (THRR) were recorded at 7 different time points: supine position (T_1) and supine lithotomy position before induction (T_2), the instant and 5 min after tracheal intubation (T_3,T_4), the instant and 15 min after abdominal CO_2 insufflation and trendelenburg-lithotomy position (T_5,T_6), and 10 min after the deflation abdomen (T_7), respectively. Results Compared with the baseline values at T_1, TAP was not significantly changed at T_2, T_5, or T_6 in group P, but was markedly decreased at T_3, T_4 and T_7. TAP in group S only decreased at T_4 and T_7, while it was much higher than that in group P at T_3. In group S, THRR was markedly lowered at T_3 compared with that at T_1; but in group P, it showed a significant increase at T_3. Conclusions Combined with remifentanil, propofol decreased CBF, but has no effect on the brain self-regulation. When inhaled in high concentrations, sevoflurane significantly reduces the brain self-regulation. Intraoperation pneumoperitoneum and postural factor significantly increase CBF, playing a stronger role than the narcotic drugs in clinical dosage (propofol, sevoflurane), without any influence on the brain self-regulation.